Hydraulic gear of the fottinger type



2 Sheets-Sheet l all?,

, zo 1o W. BLACK HYDRAULIC GEAR OF THE FTTINGER TYPE Filed April 5. 1958Dec. 3l, 1940.

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Inventor WILLY BLACK bc/fwy' Dec. 3l, 1940. w BLACK 2,226,801

HYDRAULIC GEAR OF THE F'ITINGER TYPE Filed April 5, 1938 2 Sheets-Sheet2 I Inventor WILLY BLACK ATTORNEY Patented ec. 3l, 194

sA'rEs PATENT OFFICE HYDRAULIC GEAR F THE FTTINGER TYPE New YorkApplication April 5, 1938, Serial No. 200,225 In Germany April 6, 1937 9Claims.

'I'his invention relates to hydraulic gear transmissions includinghydraulic gear of the Fttinger type, and more particularly thisinvention relates to the adaptation of -such hydraulic geartransmissions for the driving of automotive vehicles.

One object of my invention is to provide an improved arrangement of ahydraulic gear and a mechanical clutch whereby the efficiency of 1 thetransmission is greatly improved.

Another object of my invention is to provide an improved control for theelements of the hydraulic gear and of the mechanical clutch.

For a better understanding -of my invention, l5 together with other andfurther objects thereof, reference is had to the following descriptiontaken in connection With the accompanying drawings, and its scope willbe pointed out in the appended claims.

In the accompanying drawings, Fig. 1 is a cross-sectional elevationthrough the axis of a hydraulic gear transmission built in accordancewith my invention; Figs. 1a, 1b, and 1c are enlarged sectional views ofthe valves and over- 25 running clutch mechanism illustrated in Fig. 1;Fig. 2 is an enlarged View of the mechanical clutch illustrated in Fig.1; Fig. 3 is a sectional view of a modification of my invention; andFigs. 4 and 5 are sectional views of the control 30 valve illustrated inFig. 3, the valve being shown in a different operating position in eachof the three iigures.

Referring to Fig. 1 in detail, the hydraulic gear transmission consistsessentiallyiof a hy- 35 draulic torque converter I, a multiple diskclutch 2, and a mechanical gearing 3, operable for forward and reversedrive of a vehicle. The hydraulic torque converter is of the type known`as the Fttinger type and is disclosed in detail 40 in U. S. Patents1,199,359 and 1,199,360. It comprises a pump wheel 4, a turbine wheel 5,and a guide wheel 6. The pump wheel 4 is secured to a driving shaft 1,and the turbine wheel 5 is connected to a driven shaft 8 through a shaft45 II and the gearing 3. The guide wheel 6 is mounted in a web l0' ofthe stationary casing I0 through an overrunning clutch 9 illustrated indetail in Fig. 1c. The arrangement of this clutch is such that, lookingat Fig. 1, rotation 50 of the guide wheel is permitted in a forwarddirection and prevented in a rearward direction.

The clutch 2 which is developed as a multiple disk clutch is located atthe side of the torque converter I, one set of its disks 1 being secured55 to the driving shaft 1, while the other set II' is supported by thehollow shaft II. In this hollow shaft I I, a power piston I2 is mounted,which piston produces an engagement of the two sets of clutch disks whenmoved forward by uld pressure. 'Ihe hollow shaft II is provided with 5an extension II" which is of smaller diameter and contains a shaft I2'attached to the piston I2 and a spring I3. This spring cooperates withthe shaft I2 to hold the piston I2 in position to maintain the clutch inopen position. In Figs. 10 1 and 2, the clutch is illustrated as beingin the open position.

The piston I2 is operated by uid under pressure supplied by a pump I4mounted in the housing I0 and driven by gear I4 through gears I5 15 andI6, gear I5 being mounted on the end of the shaft portion II and thegear I6 being one of the gears in the gearing 3. Since this shaft II isdirectly connected to the turbine wheel 5, it is independent of thevehicle speed and oil pressure is available independently thereof. Theoil pump delivers oil through a pipe connection I'I controlled by avalve I9. The pipe I'I continues through a web III" in the casing I0,into an annular chamber II surrounding the hollow shaft section II" andthrough spaced holes Il" into a chamber I8 within the hollow shaftsection II". 'I'he oil pressure built up within the chamber I8 istransmitted to one side of the piston I2 by oil which is permitted toescape from the chamber I8 through a clearance space about the shaft I2'in a wall in the shaft which divides the reduced diameter section II"from the larger diameter section of the same shaft.,l Clearance space isalso provided between the web 35 I0 and the shaft II so that the oilpressure will notbuild up above a predetermined value.

The above-described arrangement of the clutch is of particular value inthat the clutch and the hydraulic gear takes up no more space than thespeed change gearing in a mechanical transmission. In this arrangement,the overrunning clutch surrounds the multiple disk clutch and the hollowshaft housing. This multiple plate clutch is used as a brake drum for aband brake 20, this brake being necessary to stop rotation of theturbine wheel when changing operations are performed in the gearing 3.

There is considerable advantage in the operation of the disk clutch bythe pressure piston as above described. 'I'he clutch disks are subjectto considerable wear and for normal mechanical operation would have tobe adjusted at frequent periods. Inview of the provision of a hydrauliccylinder, however, thestroke of 55 the piston is initially adjusted fora length which is required for the maximum wear of the disks, andtherefore, no adjustment is required during the entire life of theclutch plates.

Fig. 2 illustrates an enlarged cross-sectional view of the mechanicalclutch. In this figure, 1t is apparent that owing to the clutch spacingof the hydraulic gear and the mechanical clutch, it is possible forleakage fluid to travel through the space 2| between the shaft 1 and theweb 5' of the turbine wheel 5, and thereby, cause considerable frictionwithin the clutch during torque conversion periods. In order to preventan accumulation of oil in this chamber, a labyrinth packing 22 isprovided between the turbine wheel and the pump wheel, a leakage opening23 being provided from the inner labyrinth groove to drain oil seepingthrough this packing. Any oil that may seep past this last groove isdeviated from the clutch plates by the provision of ducts on both sidesof the clutch plates. One of these paths is through holes 25 in the core24 and through ducts 21 to a hole 28. The other path is through ducts 29and 30 to hole 28 through which this oil is forced by centrifugal force.In order to obtain satisfactory ejection of the liquid through the saidaperture, the diameter of the clutch 2 and of the hollow shaft enclosingthe clutch is made small enough so that they will be completely abovethe oil level indicated by line 3| in Fig. 1. This oil is accumulated inthe lower part of the casing I0 and is pumped into the hydraulic gear asneeded. In view of this small diameter of the clutch, it is necessary toincrease the number of clutch disks and to make these of hardened andpolished steel disks.

The mechanical gearing 3 is used for reversing operations. In theposition of the gears illustrated in Figs. lrand 2, the shaft 8 isdriven for reverse operation-.f If it is desired to run forward, thegear 33 is moved towards the left, so that its teeth 33 will engage theteeth I5 on gear I5. This provides a direct connection between theshafts II and 8.

As stated above, the auxiliary pump I4 is provided to furnish the oilfor operating the disk clutch. Oil pressure may, however, also beobtained from a pump 35 which is normally driven from the shaft 1through a gear 35' and a cooperating shaft 35". This pump normallysupplies oil to the hydraulic gearing through a conduit 31' and, througha portion of the pipe 31 and a valve 38, forces some of this oil througha cooler 36 from which it is returned to the casing I0 through a pipe36. By a manipulation of the valve 38, this oil traveling through thecooler may be deviated to flow through pipe 31 to operate the clutch.The arrangement of this valve 38 is shown in Fig. 1a. vIn the positionillustrated, a connection is made between the pipe 31 and the cooler.The valve may be turned an arcuate distance of approximately toestablish a connection to the clutch piston and simultaneously to breakthe connection to the cooler. The valve I9 connected between the pump I4and the clutch piston is an ordinary shut-off valve, as shown in Fig.1b, and can be operated to open the oil flow from the pump I4 into theconduit 31 and chamberv I8, or to shu-t off completely this supply. Itis, of course, obvious that for the purpose of obtaining the necessaryoil pressure, the two pumps may be provided, or only one of them. Forthe sake of economy. it is advisable to omit the auxiliary pump I4. In

cases where reliable operation is paramount, the auxiliary pump I4 maybe used as a standby.

In the clutch piston chamber, the valve 39 is provided to preventoperation of the clutch at low speeds of the vehicle. It is obvious thaton low speeds of a vehicle, it is desirable to operate the vehiclethrough the torque converting hydraulic gear and that the mechanicalclutch under these conditions should be maintained in open position. Inorder to prevent an inexperienced driver from closing his clutch underthese circumstances, a centrifugally operated valve 39 is provided. Thisvalve is normally held in open position by a spring 39 mounted on itsstem 39", and in such position, permits oil to escape from the pistonchamber. When the shaft is up to normal speeds, however, the pressure ofthis spring is overcome and the valve closes. so that pressure may bebuilt up in back of the piston to operate the clutch.

In the modification illustrated in Fig. 3, the transmission comprises ahydraulic torque converter member IOI, a clutch |02, and a mechanicalgear I03. The torque converter |0| comprises a pump wheel |04, a turbinewheel |05, and a guide wheel |06. The pump wheel is affixed to thedriving shaft |01, the turbine wheel is connected to a hollow shaft I5,and the gearing |03 to the shaft |08. The guide Wheel is rotatablymounted in a bearing |09 in the stationary casing ||0. It may be heldstationary by a brake mechanism |I| comprising a brake shoe |06 actingupon a brake drum ||2 attached to the guide wheel. The brake is normallyset by a spring II2 and is moved to open position by a piston ||3connected to the brake shoe through a linkage system ||3. Oil pressureis supplied by a. pump ||8 driven through suitable gearing connectionsfrom the shaft |I5.

The clutch |02 is built into the hydraulic converter as in themodification illustrated in Fig. 1. being provided with a group of disks|01' attached to the driving shaft I 01 and with a second group of disks||5' attached to the hollow shaft ||5. The piston ||6 for operating theclutch is mounted in the shaft H5, and is held in the open position by aspring |I1. The oil for operating this piston is supplied by an oil pump||8 driven from the hollow shaft ||5 through a set of gears I5', I|9,and IIB'. The oil for performing the various operations is in thepresent modification under the control of a multiple piston valve |20.This valve comprises a housing |24 within which upon a shaft I 2| aremounted pistons |22 and |23 spaced from each other. The pistons areurged towards one end of this housing by a spring |25, and are urged tothe other end of the housing by an operating lever |26. This operatinglever is connected to the pistons by a rod |2I'.

The piston assembly is operable to three operating positions, theoperating lever |26 being capable of retaining this assembly in eitherone of three positions against the pressure of the spring |25. The threerespective positions of this piston assembly are shown in Figs. 3, 4,and 5. The casing |24 is connected by five conduits |21, |28, |29, |30and |3I, to the transmission casing, to the oil pump IIB, to the clutchpiston chamber, and to the brake control means H3. The outlets to theseve conduits are spaced along the housing |24 so as to connect severalcombinations in the different positions of the piston assembly. In Fig.3, the piston assembly and the operating lever |26 are in position I.

In this position the discharge pipe |30 of the pump ||8 is connected tothe pipe |3| which opens into the casing so that the oil discharged bythe pump ||8 merely returns to the reservoir or tank from which it isbeing pumped. The disk clutch in this position, therefore, isdisengaged. The pipes |21, |28, and |29 are also connected to eachother, and since no pressure source is available the brake is set by itsspring H2, the guide wheel |06 being thus held stationary and thehydraulic gear operates as a torque converter.

When the lever |26 is moved to position II, as illustrated in Fig. 4,the connection between the pressure pipe 30 and the pipe |3l is brokenand the connection between the pressure pipe |30 and pipes |28 and |29is established. Pressure, therefore, is placed upon the piston ||3 torelease the guide brake and pressure is placed through conduit |29 uponthe piston ||6 to close-the clutch. In this position of the lever |26,which is designated as position II, the guide wheel |06 is released, anda direct drive connection is established by the clutch |02 between thehollow driven shaftl and the drive shaft |01.

In the position shown in Fig. 5, in which the lever |26 assumes positionIII, the pipe |28 is disconnected frpm the oil pressure pipe |30 and isconnected through pipe |21 to the oil reservoir in casing ||0. Thepressure piston ||3 is, therefore, relieved and the brake is again setto hold the guide wheel |06 stationary. 'Ihe connection between pipes|30 and |29 is maintained in this position, so that the direct driveconnection between shafts |01 and H5 is maintained. In this position,there is, therefore, a resistance to the rotation of the elements withinthe hydraulic converter, and ya substantial braking effect is obtained.

In Fig. 5, an interlock between the fuel control lever |32 and thehydraulic gear control valve is illustrated. A cam |33 is attached tothe fuel control lever |32 and cooperates with a shaft |34 attached tothe piston assembly within the valve |20. The cam surface is so arrangedthat when the fuel lever |32 is in its upper position, that is, in aposition in which substantially no fuel is being fed to the prime mover,the shaft |34 will permit .the cylinder assembly to assume its thirdposition in which a direct connection between the shafts is permittedand a braking action is obtained by holding stationary the guide wheel|06. When fuel is fed to the engine, however, by the moving of the fuellever |32, the cam surface |33 functions to move the shaft |34 and thecylinder assembly to the position illustrated in Fig. 4 wherein theguide wheel is released and only the clutch is closed for direct drivebetween the driving and driven shafts.

I claim:

1. In a hydraulic gear of the Fttinger type, the combination of astationary casing, a pump wheel, and a turbine wheel, a hollow shaftsupporting said turbine wheel within said casing, a drive shaftsupporting said pump wheel and projecting into said hollow shaft,cooperating clutch plates mounted respectively on the inner surface ofsaid hollow shaft and upon said drive shaft, and a piston within saidhollow shaft and operable by oil under pressure on one side of saidpiston to establish an engagement of said clutch plates.

2. In a hydraulic gear of the Fttinger type, the combination of astationary casing, a pump wheel, and a turbine wheel, a hollow shaftsupporting said turbine wheel within said casing, a drive shaftsupporting said pump wheel and projecting into said hollow shaft,cooperating clutch plates mounted respectively on the inner surface ofsaid hollow shaft and upon said drive shaft, a piston within said hollowshaft and operable by oil under pressure on one side of said piston toestablish an engagement of said clutch plates, and a pump in saidstationary casing connected to said hollow shaft and operable by saiddrive shaft to supply oil simultaneously from said casing to the saidturbine and pump wheels and to said hollow shaft for operating saidclutch piston.

3. In a hydraulic gear of the Fttinger type comprising a stationary gearcasing, a pump wheel, a turbine wheel, a hollow shaft attached to saidturbine wheel, a drive shaft projecting through said casing into saidhollow shaft and supporting said pump wheel, cooperating clutch platesattached to said hollow shaft and to said drive shaft respectively, aiiuid operated piston operable by oil pressure to produce an engagementof said cooperating clutch plates and a centrifugally operated valve insaid hollow shaft normally held in an open position to prevent theoperation of said piston and operable to a closed position when saidhollow shaft has attained a predetermined speed.

4. In a hydraulic gear of the Fttinger type comprising a stationary gearcasing, a pump wheel, a turbine wheel, a hollow shaft attached to saidturbine wheel, a drive shaft projecting through said casing into saidhollow shaft and supporting said pump wheel, cooperating clutch platesattached to said drive shaft and the inner surface of said hollow shaftrespectively, a uid operated piston for operating said clutch plates,and a band brake cooperating with the outer surface of said hollow shaftfor braking said driven shaft.

5. In a hydraulic gear of the Fttinger type comprising a stationarycasing, a pump wheel, a turbine wheel, a guide wheel, braking means forholding said guide wheel stationary, clutching means including a hollowshaft for supporting said turbine wheel, a second shaft supporting saidpump wheel and projecting into said hollow shaft, cooperating clutchplates mounted on the inner surface of said hollow shaft and upon saiddriving shaft, and a piston within said hollow shaft for operating saidplates to connect said driving and driven shafts, vand means forsimultaneously controlling said guide wheel brake and said clutchpiston.

6. In a power transmission, the combination of a hydraulic gear of theFttinger type including a pump wheel, a turbine wheel, a hollow shaftsupporting said turbine wheel, a drive shaft supporting said pump wheeland projecting into said hollow shaft, clutch plates in said hollowshaft attached respectively to said hollow shaft and to said driveshaft, a guide wheel, a casing support- K projecting into said hollowshaft, cooperating clutch plates in said hollow shaft attachedrespectively to said hollow shaft and to said driving shaft, ahydraulically operated piston for controlling the operation of saidclutch plates, an oil pump in said stationary casing connected to supplyoil under pressure to said guide wheel brake and to said clutch piston,and a control valve operable to one position to apply said guide wheelbrake and to close said clutch simultaneously, and operable to otherpositions to apply said brake and close said clutch respectively.

8. In a hydraulic transmission of the Fttinger type including astationary casing, a pump wheel, a turbine wheel, a guide wheel, brakingmeans for holding said guide wheel stationary, a mechanical clutchincluding a hollow shaft supporting said turbine wheel, a drive shaftsupporting said pump wheel and projecting into said hollow shaft,cooperating clutch plates in said hollow shaft, and a hydraulicallyoperated piston for controlling the operation of said clutch plates, apump in said casing connected to supply oil for operating said guidewheel brake and said clutch, a control valve operable to cause theoperation of said brake and clutch simultaneously or alternately, a fuelsupply lever, and interlocking means between said lever and controlvalve operable to shift said control valve from the position in whichsaid brake and said clutch are applied and closed simultaneously to aposition where said guide wheel brake is released and the said clutch isheld closed upon actuation of' said fuel supply lever.

9. In a. hydraulic transmission of the Fttinger type including astationary casing, a pump wheel, a turbine wheel, a guide wheel, brakingmeans for holding said guide wheel stationary, a mechanical clutchincluding a hollow shaft supporting said turbine wheel, a drive shaftsupporting said pump wheel and projecting into said hollow shaft,cooperating clutch plates in said hollow shaft, and a hydraulicallyoperated piston for controlling the operation of said clutch plates, apump in said casing connected to supply oil for operating said guidewheel brake and said clutch, a control valve operable to cause theoperation of said brake and clutch simultaneously or alternately, a fuelsupply lever, and interlocking means between said lever and controlvalve operable to shift said control valve from the vehicle retardingposition to a vehicle running position upon actuation of said fuelsupply lever.

WILLY BLACK

